PROJECT SUMMARY Throughout history, infectious diseases have been, and continue to be, a leading cause of morbidity and mortality throughout the world. While all ages are affected by infectious diseases, the ends of the spectrum of life (young children and elderly) are particularly vulnerable. Thus, the prevention and treatment of infectious diseases through the development of vaccines, therapeutics, devices and diagnostics is a critical global priority. As a VTEU for nearly 25 years, we have provided the scientific, clinical, administrative, and organizational structure to support implementation of clinical trials and studies for the Division of Microbiology and Infectious Diseases (DMID) including respiratory infections, enteric diseases, sexually transmitted infections and neglected tropical diseases. Also, we are recognized experts in the area of human challenge infection models (CHIMs) of enteric and respiratory pathogens. Additionally we repeatedly have demonstrated the ability to provide surge capacity to address infectious disease outbreaks as evidenced by our responses to the testing of H5N1 and novel H1N1 influenza vaccines (for which we received a personal letter from Dr Anthony Fauci). To further expand the capabilities of our Unit; we have added expertise in epidemiology and vaccine effectiveness. We consistently have met or exceed enrollment goals and routinely have over 90% of our subjects complete the study. We consistently have exceeded contractual obligations, including rapid recruitment of subjects spanning the age spectrum including pregnant women. We have provided outstanding leadership of multi-center studies and have been excellent collaborators on studies led by other VTEU sites. We have developed investigator initiated trials and have assisted in the development of trials initiated by DMID. We also have undertaken vaccine projects incorporating systems biology to more deeply understand correlates of vaccine-induced immunity. We are extremely excited to continue as a VTEU, collaborating with the IDCRC, the Leadership Group, NIAID, and other Infectious Diseases experts under this NIAID Cooperative Agreement.